I subscribe to Verizon DSL, and spent an entire week in a futile attempt to get the Westell 2200 usb modem to work. Conclusion: it may be possible, but it sure isn't worth the effort.
After reading other posts about usb dsl modems here at linuxquestions.org, I went out and picked up a 3Com 10/100 Network Interface Card (NIC), installed it in my machine using Win98, and replaced the usb cord with the ethernet cord included with the original package from Verizon.
When I brought up Linux (SuSE 9.0) it recognized the new card, I configured it (get everything from the gateway), and that was all it took. I opened a console window and pinged
www.yahoo.com, no trouble at all. After so many fruitless hours, oh what a feeling!
So the best way to configure the usb modem for Verizon DSL in Linux is to dispense with the usb connection. Ethernet is the answer. If you need more specifics, feel free to contact me.
Ed
PS: In case you're wary about installing new hardware, this was my first attempt to open the cover and install a new card, and it was a piece of cake.